1. Field of the Invention
This invention relates to high-pressure pumps, and more specifically to the intake and delivery valves thereof.
2. Description of Related Art
In high-pressure pumps the intake and pressurized fluid delivery valves are among the components subjected to greatest wear, and consequently require frequent replacement.
To facilitate this operation, the manufacturers of this type of pump make these valves accessible from the outside. In particular, they are inserted into a cylindrical chamber formed within the pump body and maintained in position by a retention plug, which also prevents fluid seepage to the outside of the pump.
The plug is subjected to a very high outward thrust, due to the liquid pressure which can reach more than 200 atmospheres, and is maintained in position by a thread.
A seal gasket positioned between said thread and the end of the plug provides the liquid seal.
With this type of arrangement, during pump operation the pressurized fluid necessarily wets the plug thread, giving rise to incrustation due to deposits from the pumped fluids, which make it difficult to unscrew the plug to replace the valve.
In addition the gasket seals about a diameter which is necessarily greater than the maximum diameter of the threaded part of the plug, with negative consequences on the thrust which the pumped liquid exerts on the plug.